Amoxicillin (AMX), which is one of the β-lactam antibiotics used in the treatment of bacterial infections, is known to have a serious mechanism of resistance necessitating continuous monitoring of its level in pharmaceutical and serum samples. In this study, we presented selective, accurate, and precise square wave voltammetric method based on poly(4-amino-3-hydroxynaphthalene-1-sulfonic acid) modified glassy carbon electrode (poly(AHNSA/GCE)) for determination of amoxicillin in four selected tablet brands. Appearance of a peak in the oxidative scan direction without a peak in the reductive direction of cyclic voltammograms of both bare GCE and poly(AHNSA/GCE) with four folds current and much reduced potential on the modified electrode showed catalytic property of the modifier towards oxidation of AMX. While cyclic voltammetric studies of effect of scan rate showed predominantly diffusion controlled oxidation of AMX with one electron participation, effect of pH revealed participation of protons and electrons in a 1:1 ratio. The square wave voltammetric peak current response of the modified electrode for AMX showed linear dependence on the concentration of the spiked standard AMX in the range 10–150 µmol L−1 with 9.9 nmol L−1 LOD. The AMX content of the studied tablet brands were found in the range 97.84–100.78% of the labeled value. Spike recovery results of 99.6–100.5%, and interference recovery results of 95.4–100.8% AMX in the presence of 50–200% of ampicillin and cloxicillin validated the applicability of the method for determination of amoxicillin in tablet formulation. In contrast to the previously reported works on determination of amoxicillin, the present method showed an excellent performance making it a potential method for determination of amoxicillin in real samples including serum samples.

中文翻译：

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聚(4-氨基-3-羟基萘-1-磺酸)修饰玻碳电极用于方波伏安法测定四个片剂品牌中的阿莫西林


阿莫西林 (AMX) 是一种用于治疗细菌感染的 β-内酰胺类抗生素，已知其具有严重的耐药机制，因此需要持续监测其在药物和血清样本中的水平。在本研究中，我们提出了基于聚（4-氨基-3-羟基萘-1-磺酸）修饰玻碳电极（聚（AHNSA/GCE））的选择性、准确度和精密方波伏安法，用于测定阿莫西林四个选定的平板电脑品牌。裸GCE和聚(AHNSA/GCE)的循环伏安图在氧化扫描方向上出现峰，而在修饰电极上电位大大降低的四倍电流和还原方向上出现峰，这表明修饰剂对氧化的催化性能AMX 的。虽然扫描速率影响的循环伏安研究表明 AMX 主要是由一个电子参与的扩散控制氧化，但 pH 值的影响揭示了质子和电子以 1:1 的比例参与。 AMX 修饰电极的方波伏安峰值电流响应显示，在 10–150 µmol L−1 范围内（LOD 为 9.9 nmol L−1），与加标标准 AMX 的浓度呈线性相关。研究发现，所研究的片剂品牌的 AMX 含量在标签值的 97.84-100.78% 范围内。在 50-200% 氨苄西林和邻氯西林存在下，加标回收率结果为 99.6-100.5%，干扰回收率结果为 95.4-100.8% AMX，验证了该方法测定片剂配方中阿莫西林的适用性。 与之前报道的阿莫西林测定工作相比，本方法表现出优异的性能，使其成为测定实际样品（包括血清样品）中阿莫西林的潜在方法。